Heat sink



FIG. 1 is a perspective view of a heat sink in accordance with ourdesign;

FIG. 2 is a top view thereof;

FIG. 3 is a sectional view taken along line 3—3 in FIG. 2; and,

FIG. 4 is a bottom view thereof.

The broken line showing portions of the heat sink is for illustrativepurposes only and forms no part of the claimed design.

Any shading on the figures is provided only to distinguish between theflat and contoured portions of the device, such shading patterns are notintended to be viewed as part of the claimed heat sink design.

The ornamental design for a heat sink, as shown and described.